TriAxis outputs not working

[RobertH]

Awhile back I went to play through my rig and 20 seconds after firing it up the volume faded out. The first thing I did was change out all the tubes with ones that I knew were o.k. no change. I opened it up took a look around nothing fried. Then I checked to see if I was getting signal from the fx loop and I was, both outputs work, but neither the main outputs or the record outs are working (if I crank the volume I can hear a slight signal but compared to the fx loop it's barely anything). Any ideas?

 

[18&Life]

I'm too scared, here in Brazil there isn't a place to fix boogies !
If mine break ... :?
dude I'm too scared right now :shock: :shock: :shock:

 

[disassembled]

Have you tried turning the loop off?


Greg

 

[RobertH]

Have you tried turning the loop off?


Greg

Yeah, I tried that and it's the same. The problem is definitely after the loop, I just can't narrow down the problem to a specific part failure :x

 

[disassembled]

You will have to do some signal tracing inside the amp to see where it is getting cut off. The schematics for the output section are on tubefreak.com

Greg

 

[RobertH]

You will have to do some signal tracing inside the amp to see where it is getting cut off. The schematics for the output section are on tubefreak.com

Greg

I've done a bit of that and couldn't find anything out of spec.

 

[disassembled]

You used a probe to test where the sound is getting stopped at?


I was reffering to using a signal generator (can be electronic test equipment, a cd player or something of that nature) to track down where the signal is getting cut off before it hits the outputs.

Greg

 

[RobertH]

No, I've just been checking with my multimeter.

 

[18&Life]

I'm scared a lot more :shock: :shock: :shock:

 

[disassembled]

No, I've just been checking with my multimeter.

If you don't know where the signal stops a multimeter isn't going to help you much.


Greg

 

[bunyok23]

check those big resistors near the output tubes.

the easiest way to troubleshoot is use your power amp as a audio probe.probe points in the schematic flow until you figure out where the output is off.then you'll find the culprit. it can be lots of things though